conflict3 is a plugin for Vim 8 and NeoVim that helps you resolve merge conflicts quickly.
Use your favorite package manager. If you don't have one, you can use your editor's built-in package facility. For Vim 8 users:
mkdir -p ~/.vim/pack/conflict3/start
git clone https://github.com/mkotha/conflict3 ~/.vim/pack/conflict3/start/conflict3
For NeoVim users:
mkdir -p ~/.local/share/nvim/site/pack/conflict3/start
git clone https://github.com/mkotha/conflict3 ~/.local/share/nvim/site/pack/conflict3/start/conflict3
conflict3 does not directly interact with a revision control system. Instead, it operates on a file containing diff3-style conflict markers.
In order to use conflict3 with your revision control system, you need to configure your revision control system to leave diff3-style conflict markers in files.
If you are a git user, you can do so with the following command:
git config --global merge.conflictstyle diff3
Open a file with a conflict, then use the :Conflict3Highlight command to
highlight diffs in a conflict your cursor is in, or the next one it isn't in
any. The :Conflict3Clear removes highlights.
The :Conflict3ResolveAll command tries to automatically resolve as many parts
of the conflict as possible. :Conflict3ResolveOne resolves just one fragment
instead. :Conflict3Shrink! tries to move text out of the conflict.
It is suggested that you map these commands to an easy-to-use key sequence. For example, in your .vimrc:
nnoremap <Leader>c :Conflict3Highlight<CR>
nnoremap <Leader>r :Conflict3ResolveAll \| Conflict3Shrink!<CR>
See the documentation (:help conflict3.txt or
online) for
more details.
vimdiff works great for simple 2-way merges, as long as you remember what
changes you made to one of the versions. However it quickly becomes unusable for
more complex situations due to various reasons. I enumerate some of them below.
When working on a 504E conflict, it is often very helpful to see 3 versions rathar than two. By having access to the base version (or the common ancestor) in addition to the two versions you are trying to merge, you see exactly which changes have happened to each of the versions. Conflict resolution is then the matter of transplanting one of the changes onto the other version.
vimdiff poorly deals with this type of 3-way merge, because it doesn't know
which one is the base. Typically a large amount of text is highlighted, because
vimdiff compares all three versions at the same time. This means it's hard to
see which part is modified by only one of the versions, and which part is
modified by both.
Another problem that arises when using vimdiff for a 3-way merge is that
it does not offer a good way to resolve a large conflict incrementally.
Ideally it should be possible to partially resolve a conflict, and easily see
which part has been resolved and which part still needs resolution.
A last problem is that it sometimes fails to match lines properly, leading to unreadable diffs.
conflict3 is designed to solve all these problems.
-
It highlights exactly those parts that have changed in each version, in different colors.
-
It works directly on a file with conflict markers, and supports a way to incrementally resolve conflicts: it allows you to partially resolve a conflict by simplifying it. That is, turning it into a less complicated, but still valid, conflict.
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It uses a line-matching algorithm that is aware of similarity between lines, and often produces more sensible diffs when a large number of consecutive lines are modified.